The patent to N.F. Beasley U.S. Pat. No. 3,221,733 discloses a pressure breathing therapy unit of the I.P.P.B. type, including a motor-driven air pump, a flow divider having branched outlets to a nebulizer supply conduit and to a flow and pressure regulator, and a nebulizer having a supply conduit and an automatic valve which opens during inspiration and closes at the beginning of expiration, bypassing the expired air through a relief valve.
The patent to Joseph Blasko U.S. Pat. No. 3,613,677 discloses a portable resuscitator including a carrying case, a pressurized oxygen bottle delivering through a pressure regulator to a bellows pump which, during an exhaust stroke, delivers oxygen to a face mask through a flexible hose and, during an intake stroke, draws oxygen from the bottle, the mask having a valve which closes during such intake stroke.
The patent to Ziermann, U.S. Pat. No. 3,379,194 discloses a respirator mounted in a carrying case, embodying a nebulizer which draws compressed air through a fluid amplifyer. The nebulizer provides medication where needed.
The patent to Enfield and Gandi, U.S. Pat. No. 3,874,379 discloses a nebulizer having a valve for facilitating inhalation of an aerosol by a patient and removal of exhaled gases from the patient.